more more more power

[usmceric1]

Sorry to beat a dead horse. Alright I have been readin this forum for hours looking for suggestions on a L31 rebuild. There are so many options. My head is about to explode. 355 or 383, or even keep the 350. So many differents cams. Exhaust, Intake...tuning, tuning, tuning. Gear ratios, torque converters, roller rockers, springs yada yada yada.....So I will go ahead and just ask. I know this most likely has been asked before, but I want my own answers.

I have a 96 L31, bone stock. It has 167k. It runs perfect now, but as any V8 owner on this forum I want more more more .....someday. So a HT383E is about 4500-5000. So say that is my budget. (Its cheaper than a new truck). I want to do a rebuild, but have enough money to replace my twig 10 bolt rear with a SF 14 bolt 6 lug, or maybe a FF 14 bolt with a 6 lug conversion.

Alright, I need part ideas, from crank, cams, head ideas, to exhaust and intake. What should I do. I want about 350hp to the wheels. But most of all I want more torque. Thats what a truck should be...torquey!! Hence the upgraded rear axle. Also I most likey would need to build the stock trans as well. It is the 4l60E. I know no matter what I do that I will spend a good amount of money tuning my "new" setup. So let the suggestions and dreams fly.

[19doug90]

first decide if youre going to build a 383 or a 350/355

if youre building a 355 you can just buy new pistons and have the crank/rods/pistons balanced at a machine shop.

If youre building a 383 just buy a cast rotating assembly dont need anything horribly strong for the kind of power youre shooting for

btw 400 engine hp is very possible with stock or mildly ported vortec heads. Good for about 330 hp in my camaro with a manual, but thats a lot less drivetrain loss then youll see in a truck, so probably only make 300 to the wheels.

if you really want 350 to the wheels youre probably going to be buying a 383 rotating assembly and some aluminum heads (id reccomend the edelbrock e-tec 200cc heads)

mind you if you decided to build a 383 with aluminum heads and all the goodies youll need be thinking about spending 7000-9000 dollars by the time its tuned and all the labour is done (if someone else is doing the isntall that is)

the 355 rebuild is the much cheaper option. If youre going to use the stock heads regardless just stick to a 355. IMO stock vortec heads dont flow anywhere enough air to warrant building a 383, even though many people on here disagree with me.

[usmceric1]

Yeah, I don't know about 7000-9000 dollars. Maybe around 5000 tops. Remember I want to change out the rear axle to a stronger unit. So a strong running 355? Hmmmm does not sound to shabby...

[19doug90]

stock vortec heads are quite descent on the intake side and garbage on the exhaust.

The best thing is to take the heads to somewhere that does machine work and get them to do a little bit of port work to the exhaust side where its needed most. Just be careful head work is expensive, and i know enough people that went to get a little bit of work on heads and ended up spending enough cash that for an extra 400 bucks could have had aftermarket aluminum heads.

If youre running the vortec heads as is use a ZZ4 cam, it has more lift and duration then is needed on the exhaust side which is good because it gives just a little bit of extra time to let the exhaust gasses out, since the exhaust side doesnt flow that well.

if you get port work done on the heads theres a lingenfelter cam that makes .489/.489 lift that would be ideal. Single pattern cams are meant for heads that flow well on the exhaust side.

For the valvetrain there is a set of springs/retainers that work so you dont have to machine down the guide boss, i always forget what they are but im sure pauly will chime in at some point.

That being said you can use your stock 1.5 rockers and replacing the lifters is probably not a bad idea. Better to not risk having an old lifter fail and take out your valvetrain/cam.

So ya tear the motor down, have the block machined decked etc, get new pistons if need be (probably will) and just re-use the stock crank and rods (have the machine shop check them for cracks, they will tell you if they are re-useable). Might as well have it bored .030 over since youll be buying new pistons and then itll be a 355.

Then slap your vortec heads on and either a zz4 cam or that lingenfelter one, and possibly think about doing some sort of intake conversion wether it be marine intake or something else. Keep in mind just about any of the other intake swaps will end up requiring you either delete your a/c or completly change the pulley setup/brackets everything.

While youre doing all this, now would be a good time to delete the belt driven fan and put a nice electric fan in its place.

Also if i were you i would do a 411 ECM swap. www.wait4meperformance.com quoted me 160 dollars shipping included for the ecm with mild performance modification based on the setup youre running. The swap simply involves re-pinning the connector for your ecm into the connector for the LS1 ecm, which really isnt that hard.

obviously youre going to want to add an exhaust system. If you dont have emissions testing i would reccomend ditching your EGR at this point, which the new tune btw can easily edit out of the computer.

these are all just my opinions, lots of people go about things in all sorts of different (and often rediculous lol) ways so just take all of these as sugestions. This is simply what i plan on doing with my 350 vortec motor in the near future

[5.7L JWL]

All of that sounds good, but do you have any sugg. for the
HT383E vs doing all that work on the motor "you" already have. What I mean is "downtime" rebuilding the old, plus retune
vs drop in the new HT, and retune. I ask this because with all the work and time that goes into building the old one I feel (IMPO)you are not that much ahead than buying a crate motor that comes with a warr. I know money wise you might be ahead, but what about someone who is considering this as his daily driver and time is money.

[19doug90]

theres nothing wrong with that crate motor if you want to go that way. Even still might be cheaper to just buy a shortblock and have who ever is doing the engine swap just move your heads and intake onto it. That shouldnt take more then a half day extra for a good shop to deal with

[Heslekrants]

The total cost for my 383 was $4,500 including the new stroker oil pan to clear the 6" rods, 1.6 stainless steel roller rocker, headers, shortblock built by link below, Patriot aluminium heads, Com Cams roller cam & lifters, reprogrammed ECM and whatever else need to make it run.

Here's an add for M&R

[5.7L JWL]

Nice motor man. All of that for $4500. sounds like you got a deal. where did you get the heads,rockers,cam, rods,pistons,pan, and valve covers from? What kind of HP and TQ #'s and what is your mileage? I know it's in a Burb but would like to know anyway.

[19doug90]

Originally Posted by Heslekrants

The total cost for my 383 was $4,500 including the new stroker oil pan to clear the 6" rods, 1.6 stainless steel roller rocker, headers, shortblock built by link below, Patriot aluminium heads, Com Cams roller cam & lifters, reprogrammed ECM and whatever else need to make it run.

]

those are awesome heads, what size are you running with the 383 and what cam?

im planning on running a set of patriot probably 195's with a big cam in the 355 thats in my third gen

[05BlackCrew]

Originally Posted by Heslekrants

The total cost for my 383 was $4,500 including the new stroker oil pan to clear the 6" rods, 1.6 stainless steel roller rocker, headers, shortblock built by link below, Patriot aluminium heads, Com Cams roller cam & lifters, reprogrammed ECM and whatever else need to make it run.

Here's an add for M&R

Whats the hp and tq numbers?

[Heslekrants]

I have the 195cc Patriot aluminium heads upgraded with bigger springs and 7/16 studs. Awesome heads for the money but if you got the cash go with the AFR heads.

I have a 270H Comp Cam(08-420-8) with 1.6 roller rockers puts my specs at: .533 lift, 215 dur at .050, and 110 LSA.

I bought my heads, rockers, pushrods from whiteperformance1 on Ebay and had great customer service.

I bought the cam & lifters locally.

I only have 100 miles on the new motor so not sure on mileage. I'll give her 500 miles before standing on it but there is a bunch more power on tap than the 350 had.

[5.7L JWL]

MPFI conv. Is this whats in the photo in your "My Gallery" ? It looks like a stock intake. Are you talking about the aftermarket poppets?

[Heslekrants]

The MPFI conv. eliminates the poppets and puts the injectors at each intake port. For info & pictures checkout the link below.

Vortec CSFI to MPFI conversion

[usmceric1]

Thats an awesome motor!! Something like that is exactly what I am looking for. One really good quesiton for a newb like me is: "How is the reliability on built motors like yours vs. a stock motor from the factory, assuming all things are equal i.e. taking care of its scheduled maintenance." Like I have stated before I "now" have 170k on mine and it runs very good. Alot of other owners have way more miles on thiers than I do.

Another thing is about how much money went into tuning your motor? What did you have to do to the factory computer?? Are you running a piggyback system or stock with a tune?? Did you have to upgrade the fuel system as well?? Pump all the way forward?? What about your transmission??

[Heslekrants]

The reliability of a built motor depends what you build. Built can handle way more abuse than a stock one and taken care of will last longer.

The key is to be real with what you want your truck to be. Too much cam and it'll be a high reving weekend toy.

Your drivetrain needs to handle the increase in power if you plan on driving it real hard. I spent $3K upgrading my tranny, driveshaft, rearend. I enjoy eating ricers in a Suburban...

I had PCMforLESS do a computer program for me and it's a no tools needed 2 minute swap.

The stock fuel pump can feed at least 400hp but when it starts sounding like an airplane you should replace it. That's around 100K miles for me both times.

[5.7L JWL]

Have you had a chance to figure avg. MPG?

[Heslekrants]

I'm getting around 13.5mpg mostly city and having fun while I drive. No long hwy trips yet. Have 1,500 miles on the motor now.

[TGUN]

The MPFI conv. eliminates the poppets and puts the injectors at each intake port. For info & pictures checkout the link below.

Vortec CSFI to MPFI conversion

off topic but does this conversion add any hp? or is it just reliability?

[Heslekrants]

I haven't seen any dyno numbers between the CSFI & MPFI conversion using the stock Vortec intake. The butt meter says it's better & crisper throttle response. The biggy is no more sticky poppets!

Right now I have more motor than my injectors can feed but I get emission tested every 2 years so that limits my options.

[5.7L JWL]

It's not as much as I had hoped for (for your sake) but for a K1500 Suburbus with a 383 I guess thats not too bad.